1. Field of the Invention
The present invention relates to a double-layer switchable stereo liquid crystal display and an operation method thereof, and particularly to a double-layer switchable stereo liquid crystal display and an operation method thereof that can reduce crosstalk of a three-dimensional image displayed on the double-layer switchable stereo liquid crystal display and increase luminance of a three-dimensional image or a two-dimensional image displayed on the double-layer switchable stereo liquid crystal display.
2. Description of the Prior Art
Please refer to FIG. 1 and FIG. 2. FIG. 1 is a diagram illustrating a double-layer switchable stereo liquid crystal display 100, and FIG. 2 is a diagram illustrating operation timing of the double-layer switchable stereo liquid crystal display 100 according to the prior art. As shown in FIG. 1, the double-layer switchable stereo liquid crystal display 100 includes a first liquid crystal panel 102, a backlight module 104, and a second liquid crystal panel 106. In addition, a left eye lens 1102 of a pair of polarized glasses 110 has a polarized coating of a first angle (such as) 135°, and a right eye lens 1064 of the pair of polarized glasses 110 has a polarized coating of a second angle (such as) 45°. As shown in FIG. 2, at a period T1, because the first liquid crystal panel 102 rotates liquid crystals within the first liquid crystal panel 102 according to a right eye image signal of a three-dimensional image signal received by the first liquid crystal panel 102, the backlight module 104 turns off a backlight, resulting in an observer not watching crosstalk between a left eye image and the right eye image of the three-dimensional image signal. Meanwhile, the second liquid crystal panel 106 rotates liquid crystals within the second liquid crystal panel 106 to the second angle according to a first voltage V1 received by the second liquid crystal panel 106. At a period T2 (that is, a vertical blanking interval VBLANK of the first liquid crystal panel 102), the backlight module 104 turns on the backlight. At the period T2, because the liquid crystals within the second liquid crystal panel 106 are also rotated to the second angle, a right eye of the observer can watch the right eye image signal of the three-dimensional image having polarization of the second angle through the right eye lens 1104 of the pair of polarized glasses 110. Similarly, at a period T3, because the first liquid crystal panel 102 rotates the liquid crystals within the first liquid crystal panel 102 according to the left eye image signal of the three-dimensional image signal received by the first liquid crystal panel 102, the backlight module 104 turns off the backlight, resulting in the observer not watching crosstalk between the left eye image and the right eye image of the three-dimensional image signal. Meanwhile, the second liquid crystal panel 106 rotates the liquid crystals within the second liquid crystal panel 106 to the first angle according to a second voltage V2 received by the second liquid crystal panel 106. At a period T4, the backlight module 104 turns on the backlight. At the period T4, because the liquid crystals within the second liquid crystal panel 106 are also rotated to the first angle, a left eye of the observer can watch the left eye image signal of the three-dimensional image having polarization of the first angle through the left eye lens 1102 of the pair of polarized glasses 110. In addition, as shown in FIG. 2, a period T5 is a period for the first liquid crystal panel 102 rotating the liquid crystals within the first liquid crystal panel 102 according to the right eye image signal of the three-dimensional image received by the first liquid crystal panel 102, a period T7 is a period for the first liquid crystal panel 102 rotating the liquid crystals within the first liquid crystal panel 102 according to the left eye image signal of the three-dimensional image received by the first liquid crystal panel 102, and periods T6 and T8 are periods for the backlight module 104 turning on the backlight. Thus, as shown in FIG. 2, at the period T8, the left eye of the observer can watch the left eye image of the three-dimensional image having polarization of the first angle through the left eye lens 1102 of the pair of polarized glasses 110, and at the period T6, the right eye of the observer can watch the right eye image signal of the three-dimensional image having polarization of the second angle through the right eye lens 1104 of the pair of polarized glasses 110. In addition, at the period T5, the second liquid crystal panel 106 rotates the liquid crystals within the second liquid crystal panel 106 to the second angle according to a third voltage V3 received by the second liquid crystal panel 106 to prevent the liquid crystals within the second liquid crystal panel 106 from being stuck.
However, as shown in FIG. 2, because a discharged speed of the liquid crystals within the second liquid crystal panel 106 (corresponding to the period T3 and the period T7) is faster than a charged speed of the liquid crystals within the second liquid crystal panel 106 (corresponding to the period T1 and the period T5) and a period for the second liquid crystal panel 106 rotating the liquid crystals within the second liquid crystal panel 106 to the first angle (corresponding to the periods T1 plus T2, and the periods T5 plus T6) is equal to a period for rotating the liquid crystals within the second liquid crystal panel 106 to the second angle (corresponding to the periods T3 plus T4, and the periods T7 plus T8), luminance of the left eye image of the three-dimensional image sensed by the observer is greater than luminance of the right eye image of the three-dimensional image sensed by the observer. That is to say, a luminance integration area corresponding to the left eye of the observer (a dotted line circle 202 in FIG. 2) is greater than a luminance integration area corresponding to the right eye of the observer (a dotted line circle 204 in FIG. 2), so luminance sensed by the left eye of the observer is different from luminance sensed by the right eye of the observer.